<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>基本选择器</title>
    <style>
        <!--优先级最低-->
        div{
            color:red;
        }
.cls{
    color: blue;
}
        /*id选择*/
        #d1{
           color: aquamarine;
        }
        #d2{
            color: pink;
        }
    </style>
</head>
<body>
<div>div1</div>

<div class="cls">div2</div>
<div class="cls">div3</div>

<div id="d1">div4</div>
<div id="d2">div5</div>
</body>
</html>